Alright, I have a couple ideas for characters, I wanna know if any of them would be acceptable. My main character is a man named Martin Krpan, a man in Slovene folktale who is know as a strong and imaginative man who saves an empire by beating a unbeatable man in a duel. I am also interested in the character Mephistopheles from the story of Faust. 

I know these characters are both a bit obscure, but that's the point of why I like them. Please let me know I either of them can be used.